This invention relates to a droplet dispenser and, more particularly but not exclusively, to a droplet dispenser for dispensing droplets of liquid and pasty material and to a method of dispensing droplets of pasty material.
In EP-A-0 332 287 we have described a freezer comprising a rotating drum having a cold outer surface on the top of which are deposited individual droplets of liquid or pasty material, The droplets freeze as the drum rotates and fall off the drum to form an attractive granular product.
In order to optimise this system the droplet dispenser, which comprises a reservoir with one or more dispenser tubes, should produce continuous, uninterrupted streams of separate and discrete droplets. Whilst this is relatively easy to achieve with homogeneous liquids it is difficult to achieve with pasty materials comprising small particles in a more or less viscous liquid, for example a puree such as onion puree, garlic puree, vegetable puree and fruit puree; baby food; mint sauce and horseradish sauce. Typically, the particles in these substances have a maximum dimension of 1 mm.
The problem which arises with these pasty materials is that the particles tend to block the dispenser tubes with the result that the frequency of the droplets decreases and can, in some cases, stop altogether.